Expanding boring head



April 24, 1934. Q SEVERSON 1 ,956,364

\ EXPANDING BORING HEAD Filed Sept. 22, 1931 24 m /7 Efi /7 /@Y Z/ I 6 gvwewtoz I film 351 Gummy 2%, M r/W Patented Apr. 24, 1934 UNETED STATES-'- PATE N T OF FI E EXPANDING BORING HEAD Ole Severson, Shelton, Conni, assignor to The 0. K. Tool. Company, Inc., New York, N. Y., a corporation of New York Application SeptemberZZ, 1931', Serial No. 564,292

6 Claimsr 77-58) This invention is concernedwith rotary cutting they may embody the samein the various ways tools, and specifically rotary cutting tools ofthe contemplatedbythisinvention, a drawing depicttype having removable and adjustable blades. ing a preferred typical construction has been In the interests of rigidity and simplicity a annexed-as'a part of this disclosiu'e and, in such solid cutter tool with integral cutting blades drawing, like characters of reference denote 0,

would be desirable. However, there are. other corresponding parts throughout all the views, of important desiderata which. must be taken into which: account in the achievement of a practical. tool, Figure 1 isa view in elevation of the complete among which may be noted as initial factors the cutter shown-partially inv section in order better longevity and tool cost over aperiod of time; and to disclose certain details. Fig. 2 is a View of the 5 the expediency of providing a supporting body lower end of. the cutter similar to Fig. 1 but with and cutting edges of material adapted, respecthe exterior unbroken. Fig. 3is a view similar tively, to the functions to be performed. to Fig. '2 but withthe cutter rotated 90 there- Accordingly, constructions have beendeveloped from. Fig. 4- is a plan view of the lower end.

- in which the blades are removable whereby-they Fig. 5 showsanindividual blade in elevation; and

may be made of special materials and readily Fig. 6iisalower end view of one ofthese blades. replaceable upon having become worn. As more The invention is shown applied to a boring tcol extended developments in this direction various for. which itis particularly adapted. The tool constructions have provided means for adjusting may include any conventional means for mountthe blades to prolong their life and maintain the ing in a machine, suchas the shank 10 having 75 size of the assembled cutter tool. an openingll in which the upper end portion 12 The present invention is directed to the-accomof: the cutter body 13- may be threaded. The plishment of these advantages of blade adjustlower endofthe body 13 is formed with an enment, and at the same time'a cutter tool possesslarged forked portion 14 resulting in a slot 15 in ing the rigidity and strength ofa solid cutter. which are mounted the opposed complemental so A primary feature of construction promoting such blades 16 and 17. rigidity is the provision of an arrangement The'blades 16 and 17 are provided with overwhereby, in the assembled cutter, opposed cutter lapping portions 18 and 19 respectively having blades are'not only locked in the cutter body but interfitting serrations 18a and 19a on the adare also clamped together whereby the blades are, jacent surfaces, the serrations extending at right in effect, integral and constitute the cutter proper angles to thecutter axis whereby the blades are thereby eliminating the variations resulting from capable of radial adjustment relative to each mis-alignment or disturbance of individual other but are otherwise maintained in close blades independently mounted in the cutter. alignment. The inner edges of the blades are An important feature is the ease and rapidity cut away leaving inclined cam surfaces 20 and 90 with which the cutter blades may be adjusted. 21 respectively.

To adjust the blades requires but the manipula- The lower end of the sides of the fork 14 are tion of a single clamping screw, and of a screw connected by a screw bolt 22 upon which is threaded adjusting collar which collar in its admounted a roller 23 located in the slot 15. The

vancement serves to simultaneously advance all cam surfaces 20 and 21 are adapted to simulta- 95 the blades. Because of this facility of adjustneously bear on opposite sides of this roller. ment, and also because of the exceptional ac- The cutter body 13 is provided with a threaded curacy and fineness with which adjustmentsmay portion 24 upon which is threaded a collar 25. be made, the construction is particularly adapt- A- bearing ring 26- is located between the collar able to boring tools, a necessary characteristic 25. and theupper ends'of the blades 16 and 17. of which is the maintenance of a particular A- set screw 27 projecting into the key-way 28 diameter, coupled with the ability to selectively prevents thering- 26 from turning. The threadchange the diameter in accordance with the size ed collar 25 is provided with suitable graduof the opening desired in particular cases. ations- 29 to indicate the degree of adjustment.

Other objects and advantages will be in part Advancement of the blades, it will be noted, is 05 indicated in the followingdescription and inpart accomplished through the rotation of the collar rendered apparent therefrom in connection with 25ina direction to advance it toward the lower the annexed drawing. end, engagement of the blades 16 and 17 thereby,

To enable others skilled in the art so fully'to through the bearing ring 26 forces the blades apprehend the underlying features hereof that intoengagement with the roller 23. The action 0 of the inclined surfaces 20 and 21 is then to spread the blades radially outward. When the desired adjustment has been accomplished the screw bolt 22 is tightened and the blades 16 and 17 thereby rigidly clamped in the cutter body.

Through the medium of the serrations on the opposed surfaces of the blades 16 and 17 the blades are simultaneously locked together and in effect are integral. The provision of the roller abutment 23 renders the blades self-aligning in the cutter tool the blades freely and quickly assuming a symmetrical balanced position in the cutter. As a net result the two blades cooperate as a unitary member and any such variation in the diameter, or in the position of the blades, of the cutter under the strain of cutting operations, as is frequently the case where the blades are independently mounted, is eliminated.

Adjustment of the blades is very readily accomplished requiring merely the loosening of the screw bolt 22; the advancement of the collar 25; and retightening of the screw bolt 22. Normally the screw bolt 22 is turned initially in the loosening direction but a small amount, whereby the blades are released from rigid clamping sufficient to enable the collar 25 to force them outwardly; but not rendered entirely free or loose. In some cases for very fine adjustment it may even be unnecessary to loosen the screw bolt at all.

Without further analysis the foregoing will so fully reveal the gist of this invention that others can, by applying current knowledge, readily adapt it for various utilizations by retaining one or more of the features that, from the standpoint of the prior art, fairly constitute essential characteristics of either the generic or specific aspects of this inven ion and, therefore, such adaptations should be, and are intended to be, comprehended within the meaning and range of equivalency of the appended claims.

Accordingly I claim as new and desire to secure the following combinations and elements, or equivalents thereof, by Letters Patent of United States:

1. A rotary cutter tool combining a body member having a slot therein extending axially thereof; opposed complemental blades disposed in said slot having overlapping portions, the adjacent surfaces of said portions being provided with interfitting formations extending transversely of said cutter axis and permitting independent radial movement of said blades; collar means threaded on said body member adapted to simultaneously engage an end of said blades to move the latter axially of said member; a screw bolt extending through and connecting the sides of said slot for clamping the blades therein; and a roller on said bolt disposed in said slot, said blades being provided with opposed inclined cam surfaces engaging said roller on opposite sides thereof whereby axial movement of said blades adjusts the blades radially.

2. A rotary cutter tool combining a body member having a forked end extending axially thereof; a pair of complemental blades located between the sides of said fork; complemental serrations on the adjacent surfaces of said blades extending at right angles to the axis of said cutter; a clamping bolt extending through the outer ends of said fork; a roller carried thereby located between the sides of said fork; collar means threaded on said body member adapted to engage the inner ends of said blades, the blades being provided with inclined cam surfaces engaging said roller on opposite sides thereof whereby outward advancement of said collar serves to radially advance said blades and said screw providing a means to permit said clamping bolt to be turned thereby to clamp said blades between the sides of said forked end.

3. A rotary cutter tool combining a bifurcated body member having a slot therein extending inwardly from the free end thereof and axially of said body member; a pair of complemental overlapping blades located in said slot and having cutting portions projecting beyond the end of said body member; interfitting formations of the adjacent surfaces of said blades extending transversely to the axis of said cutter; threaded means for engaging said blades to adjust the latter axially of said body member; a draw bolt connecting spaced walls of said bifurcated body member for contracting said walls and clamping the blades in said slot, said bolt being located forwardly of the point of overlap of said blades; and an abutment carried by said bolt, said blades being provided with opposed inclined cam surfaces adapted to simultaneously engage said abutment on opposite sides thereof whereby adjustment of said blades axially by said threaded means serves simultaneously to adjust said blades radially.

4. A rotary cutter tool combining a body member having a slot therein extending inwardly from the free end and axially thereof; opposed complemental blades disposed in said slot having overlapping portions, the adjacent surfaces of said portions being provided with interfitting formations extending transversely of said cutter axis and permitting independent radial movement of said blades, said blades also having cutting portions projecting beyond the free end of said body member; member adapted to simultaneously engage an end of said blades to move the latter axially of said member; an abutment roller disposed in said slot, said blades being provided with inclined cam surfaces engaging said abutment roller whereby adjustment of said collar means serves to also adjust said blades radially; and means for drawing together the sides of said slot to clamp said blades in said slot.

5. A rotary cutter tool combining a bifurcated body member having a plane walled slot therein extending inwardly from one end thereof and axially of said body member; a pair of complemental overlapping blades located in said slot and having cutting portions projecting beyond the end of said body member; a plurality of parallel interfitting formations on the adjacent surfaces of said blades extending transversely to the longitudinal axis of said tool; threaded means for engaging said blades to adjust them axially of said body member; a draw bolt connecting the spaced walls of said bifurcated body member and adapted to contract said walls and thereby clamp the blades in said slot, said bolt being located forwardly of the point of overlap of said blades; and an abutment carried by said bolt, said blades being provided with opposed inclined cam surfaces adapted simultaneously to engage said abutment on opposite sides thereof whereby adjustment of said blades axially by said threaded means serves simultaneously to adjust said blades radially.

6. An expansible rotary boring tool combining a substantially cylindrical body member having a slot providing flat parallel walls extending inwardly from the end thereof; a blade assembly comprising a pair of opposed complemental blades fitting the walls of said slot, said blades having overlapping portionsand cutting portions procollar means threaded on said body said blades radially and axially of said body member and forming positive abutments for preventing inward movement of said blades from selected adjusted positions; and means for clamping said blades together and to the walls of said slot.

OLE SEVERSON. 

